Collie Posted June 24, 2006 Share Posted June 24, 2006 Hi i have an 1987/8 e reg rxs 100 and was wondering if any other engines are a simple conversion, i just want to go to 125 really for a bit more go. or can any one give me some advice on how to get a bit more top end from it. i can get a good 60 on the flat but it i have to leather it on the hills to keep pace with the traffic. thanks Col Link to comment Share on other sites More sharing options...
Yamaha RX King Posted July 7, 2006 Share Posted July 7, 2006 Can I have your bike's pic? we in Indonesia got plenty of Yamaha Rx variants, some of their engine may fit into your bike. We got 100cc, 125cc, and most popular are 135cc Rx-King. My bike is 135cc Yamaha Rx-King, currently it ran about 140kmph with proper tuning I wonder how Rx100 looks like in England. Link to comment Share on other sites More sharing options...
Guest Yam100RX-S Posted July 20, 2006 Share Posted July 20, 2006 Hi everyone, Hopefully I will have a Yamaha 100RX-S today as a guy is coming to with a 1995 Yamaha RX-s bike, Does anyone know if a 125cc engine will fit? Link to comment Share on other sites More sharing options...
rxs100 Posted September 1, 2006 Share Posted September 1, 2006 (edited) after i bought my rxs 100 with energy induction I realised I didnt need a 125cc engine, as this bike will out-accelerate most new 125cc bikes on the market today, and even has a top speed around 10mph more. quite torquey aswell, you can put it in 5th gear from around 25mph and it accelerates whenever you pull the throttle. also easy to wheelie, although coming out of a corner in second gear above 6/7000 rpm and hammering the throttle on might not always be the best idea. if you are 17 and want to be like your mates and buy new, expensive 125cc bikes, just stop and think about this little beauty. cheap, easy to repair, and you'll beat your mates at the lights. if you are looking for a 125cc engine, there seems to be enough space to fit a DT125 or something similar. But my rxs eats DT125's Edited September 1, 2006 by rxs100 1 Link to comment Share on other sites More sharing options...
danny1989 Posted August 1, 2007 Share Posted August 1, 2007 Hi i have an 1987/8 e reg rxs 100 and was wondering if any other engines are a simple conversion, i just want to go to 125 really for a bit more go. or can any one give me some advice on how to get a bit more top end from it. i can get a good 60 on the flat but it i have to leather it on the hills to keep pace with the traffic. thanks Col i have had mine rebored and it goes like stink but its realy cheap to get done as well Link to comment Share on other sites More sharing options...
wiplash84 Posted August 2, 2007 Share Posted August 2, 2007 you can fit an yamaha rs125 into the fram as it is the same frame but you will need all the electrix as the rs125 is a points system the advantege is they will get to about 85 with proper tuning Link to comment Share on other sites More sharing options...
fosdyke Posted August 6, 2007 Share Posted August 6, 2007 Hi A rebore would be the quickest and cheapest option, but as some of the other guys say with a good tune up the RXS will eat most other 125's for breakfast so why bother - 'if it aint broke - don't fix it'!!! Link to comment Share on other sites More sharing options...
spike with the beasty rxs Posted July 10, 2008 Share Posted July 10, 2008 Can I have your bike's pic? we in Indonesia got plenty of Yamaha Rx variants, some of their engine may fit into your bike. We got 100cc, 125cc, and most popular are 135cc Rx-King. My bike is 135cc Yamaha Rx-King, currently it ran about 140kmph with proper tuning I wonder how Rx100 looks like in England. hi im spike from hastings uk & was wondering how much u can ship me over a rx-king engine for as me n a load of me m8s ride em n r gettin bored of 65-70 mph n want more grunt in the same bike cheers m8 nice1 Link to comment Share on other sites More sharing options...
spike with the beasty rxs Posted July 10, 2008 Share Posted July 10, 2008 Hi A rebore would be the quickest and cheapest option, but as some of the other guys say with a good tune up the RXS will eat most other 125's for breakfast so why bother - 'if it aint broke - don't fix it'!!! wer can i get a re-bore n how much n wats the bigest i can go 2??? please ring 07892375174 to let me no thanks spike Link to comment Share on other sites More sharing options...
Edgar-tron Posted December 10, 2019 Share Posted December 10, 2019 I had RXS100 back when they first came out, or should I say my mate brought one. He was 6’5” and weighed 1 1/2 stone more than me, and brought a new one. I had an RD125lc, but it was the Pre-restricted one at 28 BHP, so it went like F@?k. Whipped my mate easy on RXS. With his bike only 6 weeks old, we had barrel off, stuffed wood tight in top barrel and secured into vice. I told him to raise exhaust port 2mm, while I aligned intake ports with piston inlets which were quite out, I looked over and he had done 6mm !!!. I rounded exhaust port off and said it will do one of two things. I ported reed block so only 1 mm overlap on hythe Korea’s reeds. Raised main jet by 2 sizes and needle raised by 1 slot. Skimmed air filter in half and drilled another 25mm hole in lower air filter. We couldn’t get new expansion chamber, but got hold of RS all speed one, but with blow torch managed to slowly bend down pipe enough to make it fit. Well we were shocked at performance, as he out accelerated my bike then, and I brought it off him, I had each morning 56 miles to go to work, from Bethersden to hailsham, and it took me 56 min each day to do it, thus averaged 60 mph, on a 100. Ended up putting hole in piston after about 3 months, didn’t realise about heat ranges on spark plugs back then, lol. ive just brought myself another at 53 years old, and just about to do same tune, my done is 17 next June, so he’s excited about me proving it’s possible Link to comment Share on other sites More sharing options...
Recommended Posts